as.factor()函数可以将字符串变量改变为因子变量

In<br/>the previous question, by what factor doesthe<br/>pressure of the gas changes?() A: a<br/>factor of 9, B: a<br/>factor of 3, C: a<br/>factor of √3, D: a<br/>factor of 1, E: a<br/>factor of 1/3

In<br/>the previous question, by what factor doesthe<br/>rate of collisions of molecules with walls, () A: a<br/>factor of 9, B: a<br/>factor of 3, C: a<br/>factor of √3, D: a<br/>factor of 1, E: a<br/>factor of 1/3

“5P”标准是从不同角度将信用要素重新分类，它包括（）。 A: 人品因素（Personal factor）、目的因素（Purpose factor）、还款因素（Payment factor）、保障因素（Protectionfactor）和前景因素（Perspective factor） B: 价格因素（Price factor）、目的因素（Purpose factor）、还款因素（Payment factor）、保障因素（Protectionfactor）和前景因素（Perspective factor） C: 人品因素（Personal factor）、产品因素（Product factor）、还款因素（Payment factor）、保障因素（Protectionfactor）和前景因素（Perspective factor） D: 人品因素（Personal factor）、目的因素（Purpose factor）、促销因素（Promotion factor）、保障因素（Protectionfactor）和前景因素（Perspective factor）

促进HeLa细胞早熟染色体形成的MPF可以解释为： A: mitosis-promoting factor B: metaphase-promoting factor C: M-phase-promoting factor D: meiosis-promoting factor

Social culture factor research belongs to uncontrollable factor research.

Nowadays, we can use a smart phone to do almost all the payments. It belongs to ( ). A: Technological environment factor B: Economic environment factor C: Legalenvironment factor D: Social cultureenvironment factor

If demand increases by a factor of k, the optimal lot size increases by a factor of

A fixed factor is a factor of production that is used in fixed proportion to the level of output.

已知函数文件如下，则factor(4)= （） functionf=factor(n) ifn<=1f=1; elsef=factor(n-1)*n; end